Adapted from pinkparsleycatering.blogspot.com
1 large loaf of challah
8 large egg yolks
4 cups heavy cream, half-and-half, or milk; or a mixture of the three
¾ cup plus 3-4 Tablespoons sugar
¼ teaspoon salt
¼ cup vanilla extract
2 Tablespoons unsalted butter, melted.
Grease a 2 1/2-quart casserole dish. Slice the challah into 1/2-inch slices, then into cubes. In a large bowl, whisk together the egg yolks, cream, 3/4 cup sugar, salt, vanilla, and butter. Scatter about 1/4 of the bread cubes in the bottom of the dish, then pour 1/4 of the custard over them, pressing the bread cubes down to be sure they are soaked. Repeat 3 more times, pressing the mixture down between each layer. Cover the casserole dish with foil and refrigerate at least 1 hour, or overnight. Preheat the oven to 325. Place the casserole inside a larger baking dish, and fill the larger baking dish halfway with boiling water. Bake 1 1/2 hours, or until the top is light brown and set. Sprinkle the top with the remaining sugar, and place under the broiler or use a kitchen torch to melt the sugar and brown the top. The sugar will harden as it cools. Serve warm or at room temperature.